Apparatus for, and method of, providing controlled depositions on substrates

ABSTRACT

An end effector in a robotic arm assembly receives a substrate in a cassette module and moves the substrate into a process module. A turntable rotatable on a fixed axis rotates a stator and a planet in the process chamber to a position of the planet in axial alignment with the end effector in the process chamber. A lifter assembly axially aligned with, and initially axially displaced from, the axially aligned planet is moved axially to lift the substrate from the end effector. The end effector is then withdrawn by the robotic arm assembly from the process chamber and the substrate is deposited by the lifter assembly on the axially aligned planet. When successive substrates have been sequentially deposited on a plurality of planets in the process chamber in the manner described above, the planets are individually rotated by the turntable relative to the stator on a second axis displaced from the first axis. The stator has peripheral teeth which mesh with teeth on the planets, the teeth being constructed (e.g. by individual peripheral cuts) to prevent slippage in the planet rotations. A resilient member on the stator engages each planet to instantaneously brake the planets when the turntable is de-energized. A gun provides a deposition on the substrates during the rotation of the planets. In this way, each deposition on each substrate is provided with a substantially uniform thickness at the different positions on the substrate.

This invention relates to apparatus for, and methods of, providingcontrolled depositions on a substrate or wafer. The inventionparticularly relates to systems for, and methods of, providing adeposition of a substantially uniform thickness at the differentpositions on the surface of the substrate or wafer.

BACKGROUND OF THE INVENTION

Magnetic heads are provided in computers for transferring informationbetween the magnetic heads and storage media such as discs disposed incontiguous (almost abutting) relationship to the heads. The magneticmedia such as the discs are rotated by disc drives under the control ofmicrocomputers to particular positions where the transfer takes place.When the transfer is from the disc drive to the magnetic head, theinformation read by the magnetic head is processed in the microcomputerand the processed information is then transferred from the head to astorage position in the disc. The information transferred between thehead and the disc is generally in binary form.

The rate of transferring binary information between the head and thestorage medium such as the disc has been progressively increasingthrough the years. In order to transfer such information atprogressively increasing rates, the size of the heads has beenprogressively decreased. Furthermore, as the size of the heads hasprogressively decreased, the precision in the manufacture of parts inthe head has had to progressively increase in order to be able totransfer the binary information accurately between the head and the discdrive at the increased rates.

The magnetic heads include members which face the magnetic discs andprotect the magnetic heads in case the magnetic discs should crashagainst the magnetic heads as the discs rotate at high speeds. Thesemembers may be made from a suitable insulating material such as analuminum oxide with an index of refraction of at least 1.63 to providethe members with hard and dense characteristics. These members havedecreased in size in accordance with the decrease in size of the heads.Furthermore, the dimensions of these members have had to become moreprecise as the size of these members has decreased and as the rates oftransfer of the magnetic information between the heads and the discshave increased because of the rotation of the discs at increased speedsand because of the decreased size of these members. These members havebeen formed as die on a substrate.

Even as the size of the die on the substrate has tended to decreasethrough the years, the size of the substrate has tended to increase. Asthe size of the substrates has tended to increase, it has becomeprogressively difficult to fabricate the members on the die with greatprecision. For example, when the substrate has a width of approximatelysix inches (6"), hundreds, if not thousands, of the members may besimultaneously produced on the substrate. Any slight deviation indimension (e.g. thickness) at one end of the substrate may becomemagnified in die which are progressively disposed on the substratetoward the other end of the substrate.

The substrates are often fabricated on a one-at-a-time basis inprocessing equipment. As will be appreciated, this fabrication isrelatively slow even though there may be hundreds, if not thousands, ofdie on a single substrate. Processing equipment also exists fordirecting a plurality of substrates in sequence through a plurality ofsuccessive stations. Although this may be considered to constitute animprovement from a time standpoint, it still provides a processing ofonly a single substrate at any one time at each successive processingstation.

It is desirable to process a plurality of substrates simultaneously toprovide a deposition on each of the substrates with the same parameters.For example, it is desirable that the thickness of the deposition oneach die be substantially uniform at different positions on the die. Itis also desirable to process each of the substrates in the pluralitysimultaneously with great precision (e.g. substantially uniformthickness) in each of the successive processing steps. This desirabilityof being able to process a plurality of substrates simultaneously withgreat precision has been recognized for some time but no one has beenable to accomplish this until now. This has been particularly true infabricating substrates each of which has hundreds, if not thousands, ofdie for use as members in magnetic heads.

It is further desirable to provide one (1) apparatus which operates onan automatic basis to process simultaneously a plurality of substratesfrom the steps of receiving the substrates from a cassette module to thesteps of positioning the substrates on planets and then to the steps ofproviding controlled depositions on the planets. It is further desirableto provide apparatus which operates on an automatic basis to return thesubstrates to the cassette module after the controlled depositions onthe substrates.

Co-pending application 08/554,459 filed on Nov. 7, 1995, now U.S. Pat.No. 5,830,272, in the name of Robert George Begin and Peter J. Clarkefor a "SYSTEM FOR AND METHOD OF PROVIDING A CONTROLLED DEPOSITION ONWAFERS" and assigned of record to the assignee of record of thisapplication discloses and claims a system for, and method of, providingcontrolled depositions simultaneously on a plurality of substrates. Thesystem and method disclosed and claimed in co-pending application08/554,459 also provide the controlled depositions simultaneously on thesubstrate with great precision (e.g., substantially uniform thickness).The system and method disclosed and claimed in U.S. Pat. No. 5,830,272are also advantageous in that they are able to provide the controlleddepositions simultaneously on the substrates, even when the substrateshave square rather than round configurations, with great accuracy and atfast rates. The controlled depositions are able to be providedsimultaneously on the substrates after precisely positioning thesubstrates so that the successive die are substantially parallellongitudinally and laterally to the walls defining the peripheries ofthe substrates.

In one embodiment of the system and method disclosed and claimed in U.S.Pat. No. 5,830,272, a robotic arm assembly in a transport module isexpansible to have an effector at its end receive a substrate in acassette module. The robotic arm assembly is then contracted and rotatedwith the effector to have the effector face a process module. Planets ona turntable in the process module are rotatable on first parallel axes.The turntable is rotatable on a second axis parallel to the first axesto move successive planets to a position facing the effector. At thisposition, an alignment assembly is aligned with, but axially displacedfrom, one of the planets. This assembly is moved axially into coupledrelationship with such planet and is rotated to a position aligning thesubstrate on the effector axially with such planet when the arm assemblyis expanded.

A lifter assembly aligned with, and initially displaced from, suchplanet is moved axially to lift the substrate from the effector in thesystem disclosed and claimed in U.S. Pat. No. 5,830,272. The armassembly is then contracted, rotated with the effector and expanded toreceive the next cassette module substrate. The lifter assembly is thenmoved axially to deposit the substrate on the planet. When thesubstrates have been deposited on the planets as described above, theplanets are individually rotated on the first axes by the turntablerotation on the second axis with the stator braked. Guns having aparticular disposition relative to the planets provide controlleddepositions on the substrates during such planet rotations. The planetsand the effector hold the substrates at peripheral positions displacedfrom the controlled substrate depositions.

BRIEF DESCRIPTION OF THE INVENTION

An end effector in a robotic arm assembly receives a substrate in acassette module and moves the substrate into a process module. Aturntable rotatable on a first axis rotates a stator and a planet in theprocess chamber to a position of the planet in axial alignment with theend effector in the process chamber.

A lifter assembly axially aligned with, and initially axially displacedfrom, the axially aligned planet is moved axially to lift the substratefrom the end effector. The end effector is then withdrawn by the roboticarm assembly from the process chamber and the substrate is deposited bythe lifter assembly on the axially aligned planet.

When successive substrates have been sequentially deposited on aplurality of planets in the process chamber in the manner describedabove, the planets are individually rotated by the turntable relative tothe stator on a second axis displaced from the first axis.

The stator has peripheral teeth which mesh with teeth on the planets,the teeth being constructed (e.g by individual peripheral cuts) toprevent slippage in the planet rotations. A resilient member on thestator engages each planet to instantaneously brake the planets when theturntable is de-energized. A gun provides a deposition on the substrateduring the rotation of the planets. In this way, each deposition on eachsubstrate is provided with a substantially uniform thickness at thedifferent positions on the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a schematic perspective view of apparatus constituting oneembodiment of the invention for simultaneously producing a controlleddeposition on a plurality of substrates, the apparatus being seen from acassette module above and at one end of the apparatus;

FIG. 2 is a schematic perspective view of the apparatus shown in FIG. 1as seen from a process module at the other end of the apparatus;

FIG. 3 is a side elevational view of the apparatus and shows thecassette module, the process module and a transport module between thecassette module and the process module;

FIG. 4 is a top plan view of the apparatus and shows the cassettemodule, the transport module and the process module and variouscomponents and sub-assemblies at the tops of these modules;

FIG. 5 is a fragmentary perspective view of the process module, as seenfrom a position above and to the rear of the process module, with thetop cover on the process module removed;

FIG. 6 is a sectional view taken substantially on the line 6--6 of FIG.3 and illustrates in additional detail the construction of the cassettemodule, the transport module and the process module and the constructionof a robotic arm assembly and an end effector in the transport module,the robotic arm assembly being shown in one position in solid lines andin another position in broken lines;

FIG. 6A is a fragmentary top plan view of the cassette module and thetransport module and shows, in broken lines, the robotic arm assemblyand the end effector in an expanded relationship with the end effectorin the cassette module and shows, in solid lines, the robotic armassembly and the end effector in a contracted relationship with the endeffector in the transport module;

FIG. 6B is a fragmentary top plan view of the transport module and theprocess module and shows, in broken lines, the end effector in thetransport module and, in solid lines, the end effector in the processmodule;

FIG. 7 is a side elevational view, partially in section, schematicallyshowing in additional detail the construction of the cassette module andthe transport module;

FIG. 8A is an enlarged fragmentary sectional view taken substantially onthe line 8--8 of FIG. 7 and shows the disposition of a substratecassette in the cassette module and also shows the end effector in thecassette module before the disposition of one of the substrates in thecassette on the end effector;

FIG. 8B is a view similar to that shown in FIG. 8A but shows thecassette lowered in position so that one of the substrates rests on theend effector;

FIG. 8C is a view similar to that shown in FIGS. 8A and 8B but shows thecassette module lowered further to space the substrate on the endeffector from the wall defining the socket in which such substrate isseated, thereby freeing such substrate for movement from the cassette;

FIG. 9 is a top plan view of the end effector also shown in FIGS. 6A,6B, 7, 8A, 8B and 8C and is partially broken away to show components inthe end effector in section;

FIG. 10 is an enlarged fragmentary sectional view taken substantially onthe line 10--10 in FIG. 9 and shows certain components in the endeffector in additional detail;

FIG. 11 is an enlarged fragmentary sectional view of the end effectorand is taken substantially on the line 11--11 of FIG. 9;

FIG. 12 is an enlarged fragmentary sectional view of the end effectorand is taken substantially on the line 12--12 of FIG. 9;

FIG. 13 is an enlarged exploded perspective view of the end effector;

FIG. 14 is an enlarged fragmentary sectional view taken substantially onthe line 14--14 of FIG. 4 and shows the construction of the processmodule in additional detail;

FIG. 15 is an enlarged fragmentary sectional view taken substantially onthe line 15--15 of FIG. 14 and shows in plan the planet with nosubstrate on the planet, the planet being misaligned with the endeffector although this is not specifically shown in FIG. 15;

FIG. 16 is an enlarged fragmentary sectional view similar to that shownin FIG. 15 and shows in plan the planet and the substrate on the planet,the planet being aligned with the end effector although this is notspecifically shown in FIG. 16;

FIG. 17 is an enlarged fragmentary plan view, taken within the circle 17of FIG. 15, of an idler assembly for pressing the planet against astator and is partially broken away to show certain components in theidler assembly in additional detail;

FIG. 18 is a sectional view of the idler assembly and is takensubstantially on the line 18--18 of FIG. 17;

FIG. 19 is an enlarged fragmentary sectional view taken substantially onthe line 19--19 of FIG. 15 and shows in additional detail therelationship between the planet, the stator and a turntable in theprocess module;

FIG. 20 is a sectional view taken substantially on the line 20--20 ofFIG. 14 and shows the disposition of a substrate on a lifter assembly inthe process module and also shows the construction of the lifterassembly for receiving the substrate;

FIG. 21 is a fragmentary perspective view of a lifter in the lifterassembly and is partially exploded in one position to show the lifter inadditional detail;

FIG. 22 is a sectional view taken substantially on the line 22--22 ofFIG. 20 and shows the in-line relationship in the process module betweenthe planet, an alignment assembly above the planet and the lifterassembly below the planet;

FIG. 22A is an enlarged fragmentary sectional view of the planet and asubstrate on the planet and is taken within a circle designated as "A"in FIG. 22;

FIG. 23 is a simplified schematic side elevational view similar to thatshown in FIG. 14 and shows the relative dispositions of the alignmentassembly, the planet and the lifter assembly after the movement of thealignment assembly downwardly into coupled relationship with the planetto rotate the planet to a particular position;

FIG. 24 is a simplified schematic side elevational view similar to thatshown in FIG. 23 and shows the alignment assembly in upwardly displacedrelationship from the planet and additionally shows the substrate on thelifter assembly as a result of the upward movement of the lifterassembly and shows the end effector in a retracted relationship;

FIG. 25 is a simplified schematic side elevational view similar to thatshown in FIGS. 23 and 24 and shows the substrate on the planet and alsoshows, in broken lines, the lifter assembly in position to lift thesubstrate from the end effector and additionally shows, in solid lines,the position of the lifter assembly after the lifter assembly hasdeposited the substrate on the planet;

FIG. 26 is a view similar to that shown in FIGS. 24 and 25 with thesubstrate on the planet and with the lifter and alignment assembliesdisplaced axially from the planet;

FIG. 27 is a sectional view taken substantially on the lines 27--27 ofFIG. 4 and shows the turntable, the stator and one of the planets andalso shows the gun for producing the controlled deposition on thesubstrate and a shutter in position relative to the gun and the planetfor preventing the gun from producing the deposition on the substrate;

FIG. 28 is a top plan view of the turntable, the stator and the planetsand the substrates on the planets;

FIG. 29 is a sectional view taken substantially on the line 29--29 ofFIG. 28 and shows the turntable and the stator and a one-way clutch forproviding for a rotation of the stator in one direction and forpreventing the rotation of the stator in the opposite direction;

FIG. 30 is a schematic top plan view showing the relative positioning ofone of the planets, the substrate on the planet and the magnet assemblyfor producing the magnetic field during the production of a firstcontrolled deposition on the substrate;

FIG. 31 is a schematic top plan view similar to that shown in FIG. 30and shows the relative positioning of the planet, the substrate on theplanet and the magnet assembly for producing the magnetic field duringthe production on the substrate of a second controlled depositionsubstantially perpendicular to the first controlled deposition;

FIG. 32 is a schematic top plan view of the process module with thecover, the turntable and the planets removed and shows the guns in theprocess chamber with the shutters covering the guns to prevent the gunsfrom producing depositions on the substrates;

FIG. 33 is a sectional view taken substantially on the line 33-32 ofFIG. 32 and shows additional details of one of the guns for providingthe controlled deposition on a substrate and of a shutter mechanism forpreventing such a deposition;

FIG. 34 is a sectional view taken substantially on the line 34--34 ofFIG. 4 and shows an arrangement for introducing a controlled amount ofheat to the substrate to facilitate the production of the controlleddeposition on the substrate;

FIG. 35 is an enlarged fragmentary view similar to that shown in FIG. 32and shows an alternate embodiment of shutters for covering the guns;

FIG. 36 is a sectional view taken substantially on the line 36--36 ofFIG. 35 and shows additional details of one of the guns and theembodiment of the shutter mechanism shown in FIG. 35 for opening andclosing the gun;

FIG. 37 is a simplified schematic diagram of an improved gun forinclusion in the system of this invention, the gun including a pair oftargets and a pair of anodes;

FIG. 38 is a simplified circuit showing the introduction of alternatingvoltages to the targets and the anodes in the improved gun shown in FIG.37;

FIG. 39 is a schematic diagram of an arrangement for improving theuniformity of the controlled deposition on the substrates;

FIG. 40 is a flow diagram showing, on a simplified basis, the successivesteps in the operation of the apparatus shown in the previous Figures;

FIG. 41 is a schematic plan view of a stator and a plurality of planetsincluded in an improved embodiment of the invention;

FIG. 42 is an enlarged fragmentary sectional view of a portion of theidler wheel shown in FIG. 41 and is taken substantially on the line42--42 of FIG. 41;

FIG. 43 is a fragmentary sectional view in elevation and shows an O-ringdisposed on the stator and abutting one of the planets for providing abraking action to limit the movement of the planet to precise positionswhen the motor driving the planet is de-energized;

FIG. 44 is a schematic plan view taken substantially on the line 44--44of FIG. 43 and shows the interrelationship between teeth on the statorand teeth on one of the planets;

FIG. 45 is an enlarged fragmentary sectional taken within a circle 45shown in FIG. 43;

FIG. 46 is a fragmentary sectional view taken substantially on the line46--46 of FIG. 45 and shows the 0ring on the stator and schematicallyillustrates the braking action provided by the O-ring on one of theplanets;

FIG. 47 is a schematic plan view showing the area covered by adeposition gun during one movement of a planet and a substrate on theplanet past the deposition gun; and

FIG. 48 is a schematic plan view showing the area covered by adeposition gun after a particular number of movements of the planet, andthe substrate on the planet, past the deposition gun.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment of the system disclosed and claimed in U.S. Pat. No.5,830,272, apparatus generally indicated at 10 (FIG. 1) is provided forproducing controlled depositions on substrates 12 (FIGS. 6, 7, 8A, 8Band 8C). The substrates 12 may include a plurality of dies each of whichmay be disposed on a magnetic head in juxtaposition to a movable membersuch as a memory disc rotatable at a very high speed. The dies may becoated with a layer of a suitable material such as aluminum oxide (Al₂O₃) having an index of refraction such as at least 1.63 to provide thedie with a hard and dense surface. In this way, the die protects thehead from being damaged if and when the memory disc should wobble andcontact the head while the memory disc is rotating at a high speed. Thehead provides a transducing action in magnetically reading digitalinformation stored in the disc or in magnetically writing magneticinformation on the disc.

The apparatus 10 includes a cassette module, generally indicated at 14,for storing a plurality of the substrates 12 in a stacked relationship.The cassette module 14 includes a load lock 15 and a door 16 which isnormally closed and which is opened to store the substrates 12 in thecassette module. The cassette module 14 also includes an elevatorgenerally indicated at 18 (FIGS. 3 and 7) for raising or lowering thecassette in the cassette module. Vacuum pumps 20 may be disposed on thecassette module 14 to produce a vacuum in the cassette module after thesubstrates 12 have been disposed in the cassette module. Theconstruction of the cassette module 14, the load lock 15, the elevator18, and the vacuum pumps 20 are known in the prior art.

The apparatus 10 also includes a transport module generally indicated at22. The transport module includes a robotic arm assembly generallyindicated at 24 (FIGS. 6 and 7). The transport module 22 and the roboticarm assembly 24 may be considered to be known in the art although an endeffector, generally indicated at 26 in FIG. 6, at the end of the roboticarm assembly is not known in the prior art. The robotic arm assemblyincludes arms 28, 30 and 32 (FIGS. 6A and 6B) pivotable relative to oneanother between an expanded relationship shown in broken lines in FIG.6A and a contracted relationship shown in solid lines in FIG. 6A andbetween a contracted relationship shown in broken lines in FIG. 6B andshown in solid lines in FIG. 6B in an expanded relationship. The endeffector 26 is disposed at the end of the arm 32 and is constructed tohold one of the substrates 12.

In one expanded position, the robotic arm assembly 24 extends through aslot valve 34 (FIGS. 4 and 6A) into the cassette module 14 to grip oneof the substrates 12 in the cassette module. This is shown in brokenlines in FIG. 6A. The robotic arm assembly 24 is then contracted towithdraw the end effector 26 through the slot valve 34 into thetransport module 24. This is shown in broken lines in FIG. 6B. When thisoccurs, the cassette module 14 and the transport module 22 arepreferably at a vacuum pressure. The transport module 22 also includes acryogenic unit, generally indicated at 38 (FIGS. 1 and 4), foreliminating water molecules in the transport module.

With the robotic arm assembly 24 contracted in the transport module 22,the robotic arm assembly and the end effector 26 are rotated through anangle of substantially 180° so that the end effector faces a processmodule generally indicated at 36. The positions of the robotic armassembly 24 and the end effector 26 at this time are shown in brokenlines in FIG. 6B. The robotic arm assembly 24 may then be expanded tomove the end effector 26 and the substrate 12 on the end effector intothe process module 36. The position of the end effector 26 at this timeis shown in solid lines in FIG. 6B.

The construction of the process module 36 is considered to be unique.The process module 36 processes the substrates 12 transferred into theprocess module to provide the controlled depositions on the substrates.An access cover 40 is included in the process module 36 for providingaccess by a user into the process module.

A cover 42 (FIG. 2) is disposed on a housing 43 of the process module36. The cover 42 is movable upwardly and downwardly on guide rods 44 bycylinders 45 to expose or cover the members or units inside the processmodule. A shield 46 having apertures 48 is disposed on the cover 42. Theshield 46 is disposed over a heater assembly, generally indicated at 50,to protect the heater assembly and to provide for the evacuation of hotair from the heater assembly and for the introduction of cooling airinto the heating assembly.

As shown in FIG. 7, the cassette module 14 includes a cassette,generally indicated at 52, for holding a plurality of the substrates 12in a stacked relationship. The cassette 52 is movable upwardly anddownwardly by a motor 54 which rotates a lead screw 56. A nut 58 ismovable vertically on the lead screw 56 as the lead screw rotates. Thenut 58 in turn carries the cassette 52 vertically through a shaft 53.

FIGS. 8A, 8B and 8C schematically show how the substrates 12 areindividually transferred from the cassette 52 to the end effector 26. Asmay be seen in FIG. 8A, the substrates 12 are disposed in a verticallyspaced and stacked relationship in notches 58 in a wall 59 of thecassette 52. In FIG. 8A, the end effector 26 is disposed below, and invertically spaced relationship to, the bottom one 12a of the substrates12 in the cassette 52. FIG. 8B shows the cassette 52 in a loweredposition relative to that shown in FIG. 8A such that the end effector 26abuts the bottom surface of the substrate 12a in the cassette 52.

When the cassette 52 is lowered even further as shown in FIG. 8C, thesubstrate 12a is disposed in its notch 58 so that it does not contactany of the walls defining the notch. Since the end effector 26 is stillcontacting the substrate 12a at this time, the end effector is able toremove the substrate easily from the notch 58 when the robotic armassembly is moved from the expanded relationship shown in broken linesin FIG. 6A to the contracted relationship shown in solid lines in FIG.6A. The results described for removing substrates 12 from the cassette52 can also be achieved by raising and lowering the robotic arm assembly24. Such raising and lowering of the robotic arm assembly 24 areconsidered to be within the scope of this invention.

The construction of the end effector 26 is shown in detail in FIGS.9-13. The end effector 26 includes a body 60 which is provided with avent hole 62 (FIG. 9) chamfered as at 64. A hole is provided to registerthe end effector 26 on a dowel 65 (FIG. 6A) in the arm 32. The body 60is provided with a horizontal ledge 66 (FIG. 10) to receive thesubstrate 12 and with a bevelled surface 68 extending upwardly at anacute angle from the inner end of the ledge 66. The ledge 66 and thebevelled surface 68 accurately position one end of the substrate 12 asschematically shown in FIG. 10.

A pair of spaced rods 70 extend at one end into holes 71 (FIG. 11) inthe body 60. The rods 70 are fixedly positioned at that end relative tothe body 60 as by set screws 72 extending into the body. The rods 70 maybe disposed at a suitable angle such as approximately five degrees (5°)to the horizontal to accommodate any deflection resulting fromvariations in weight between different substrates.

A web, generally indicated at 74, having a bottom panel 76 is impaled onthe rods 70 by extending the rods at one end through holes 78 (FIG. 13)in a flange 80 which extends upwardly from the bottom panel in atransverse relationship (preferably at approximately an 80° angle) tothe bottom panel 76. The web 74 is also impaled by extending the rods 70through holes 86 in a clamping plate 88 and through holes 82 in a flange84 at the other end of the bottom panel 76. The flange 84 issubstantially perpendicular to the bottom panel 76.

The rods 70 then extend from the flange 84 into the holes 71 in the body60. The clamping plate 88 is biased outwardly from the rods 70 againstthe flange 84 by helical springs 90 which extend in a constrainedrelationship from holes 92 in the body 60 against the flange 84. A screw94 extends through a hole 96 in the clamping plate 88 into a hole 98 inthe body 60. The screw 94 is adjustable in the hole 98 to adjust thebias exerted by the helical springs 90 against the flange 84 and theclamping plate 88.

The end effector 26 provides a balanced arrangement which contacts thesubstrate 12 only at positions at the opposite ends of the substratewhere depositions are not provided on the substrate. As a result, theend effector 26 lifts the substrate 12a from the cassette 52 andtransfers the substrate through the transport module 22 to the processmodule 36 without scratching the surface of the substrate in the workingarea where the controlled deposition is to be provided on the substrate.The substrate 12 is engaged on the end effector 26 by being disposed atone end on the ledge 66 (FIG. 10) and by being disposed at the other endagainst the flange 80.

The end effector 26 is balanced by adjusting the positioning of thescrew 94 in the hole 98 in the body 60 to produce adjustments in theforces exerted by the springs 90 against the flange 84 and the clampingplate 88. The springs 92 then act to balance the forces at the oppositeends of the flange 84 and the clamping plate 88 so that the forces aredistributed across the width of the end effector 26. The rods 70 contactthe substrate 12 at the position where the rods extend through the holes78 (FIG. 13) in the flange 80. The rods 70 serve primarily as backbonesto support and position the web 74 relative to the body 60.

The substrates 12 are preferably square. They are deposited on planets100 (FIG. 14) in the process module 36 so that they have a precisedisposition on the planets. As will be seen in FIGS. 5 and 6, there arepreferably four (4) planets 100 in the process module 36. Each planet isdisposed on a turntable 102 to be rotatable with the turntable on a hub104 (FIG. 27). The centers of the planets 100 are spaced the same radialdistance from the center of the hub 104. The planets 100 are angularlyspaced from one another by angles of substantially 90° relative to thehub 104.

Each of the planets 100 includes permanent magnets 106 (FIGS. 15 and 16)disposed at opposite ends of the planet and also includes magnetic polepieces 108 which define substantially a rectangular enclosure providinga closed loop for the creation of a magnetic field. The construction anddisposition of the permanent magnets 106 and the pole pieces 108 inapparatus for providing controlled depositions on the substrate 12 arewell known in the art.

The turntable 102 is rotated on the hub 104 to dispose each of theplanets 100 in position to receive one of the substrates 12 from the endeffector 26. For example, the planet 100 is in position in FIG. 6 toreceive the substrate 12a (FIGS. 8A, 8B and 8C) on the end effector 26.When the turntable 102 has rotated the planet 100a to the position forreceiving the substrate 12a, as shown in FIG. 6, an alignment assemblygenerally indicated at 110 in FIG. 14 becomes operative to rotate theplanet 100a on the axis of the planet to position the planet to receivethe substrate 12a.

The alignment assembly 110 is positioned on the same axis as the planet100a. The alignment assembly 110 includes pneumatic cylinders 112 whichoperate in conjunction with a bellows 114 to move the alignment assemblyvertically along the axis of the alignment assembly.

The alignment assembly 110 includes a drive arm 114 which extendsradially across the alignment assembly at the lower end of the alignmentassembly and which has drive pins 116 at the radially outward end of thedrive arm.

When the alignment assembly 110 has been lowered to substantially thevertical level of the planet 100 as shown in FIG. 23, the alignmentassembly is incrementally rotated by a motor 118 (FIG. 14), at the upperend of the alignment assembly. The calibrated position may be sensed andcontrolled by a sensor assembly 50 as shown in FIG. 22. The rotation ofthe motor 118 causes the drive pin 116 on the alignment assembly 110 toengage a pin 120 at the top of the planet 104 and to rotate the planetto a particular rotary position for receiving the substrate. The motor118 may be a stepper motor which is computer controlled to provide aprecise control over the positioning of the pin 116.

The operation of the motor 118 is then discontinued and the alignmentassembly 110 is withdrawn axially upwardly from the planet 100 by theoperation of the pneumatic cylinders 112 and the bellows 114. Therobotic arm assembly 24 is facing the process module 36 at this time asshown in FIG. 6B. The robotic arm assembly 24 is then expanded into theprocess module 36 (shown in solid lines in FIG. 6B) to move the effectorassembly 26 to a position above the planet so that the substrate on theend effector can be subsequently transferred to the planet. This isindicated by an arrow 121 in FIG. 24.

A lifter assembly generally indicated at 122 is disposed in the processmodule 36. The lifter assembly 122 is disposed below the planet 100a inaxial alignment with, and axial displacement from, the planet 10a. Thelifter assembly 122 is also disposed in axial alignment with thealignment assembly 110. The lifter assembly 122 is adapted to lift thesubstrate 12a from the end effector 26 and to deposit the substrate onthe planet 10a. This is accomplished after the alignment assembly 110has rotated the planet 100a to the position for receiving the substratefrom the end effector 26.

The lifter assembly 122 includes pneumatic cylinders 124 (FIG. 14) and abellows 126 corresponding to the pneumatic cylinders 112 and the bellows114 in the alignment assembly 110. The lifter assembly 122 also includesa lifter, generally indicated at 128, at the upper end of the lifterassembly. A motor 129, preferably a stepper motor, is computercontrolled to rotate the lifter 128 to the precise position forreceiving the substrate on the end effector. The incremental rotationsof the stepper motor 129 are sensed by a sensor 131 which defines ahoming position to which the lifter 128 has to be rotated to receive thesubstrate on the end effector.

As best shown in FIG. 21, the lifter 128 includes a plurality of supportarms 130 disposed around the periphery of the lifter at positionsangularly spaced 90° from one another. The support arms 130 are disposedin sockets 132 in the lifter 128 and are attached to a lifter body 133as by screws 134. The lifter assembly 122 is moved upwardly (asindicated by an arrow 135 in (FIG. 24) by the pneumatic cylinders 124 sothat the lifter 128 passes through an opening 138 in the planet 100 to aposition (FIG. 24) below and abutting the substrate 12a on the endeffector 26.

Each of the support arms 130 on the lifter 128 has a pair of pins 140.As will be seen in FIG. 20, the pins 140 on each support arm 130straddle one corner of the substrate 12a disposed on the end effector 26when the lifter 128 is moved upwardly to the position shown in FIG. 24.The straddling relationship between the pins 140 and the corners of thesubstrate 12a causes the pins 140 to abut the corners of the substrate12a when the lifter 130 is moved upwardly to lift the substrate from theend effector 26.

The pins 140 have tapered configurations as shown in FIG. 21. Because ofthis, the substrate 12a becomes adjusted in position as the substratesettles downwardly on the support arms 130. As the substrate 12a settlesdownwardly on the support arms 130 between the pins 140, the precisionof the disposition of the substrate on the support arms becomesenhanced. Thus, when this downward movement has been completed, thesubstrate 12a is precisely abutted against a pair of the pins 140 atevery corner of the substrate.

After the lifter 128 has lifted the substrate 12a from the end effector26, the robotic arm assembly 24 is contracted so that the end effector26 is withdrawn from the axis of the planet 100 and the lifter assembly122. The withdrawal of the end effector 26 from the axis of the planet100 is indicated by an arrow 141 in FIG. 24. The end effector 26 can bewithdrawn at this time because the lifter assembly 122 has been raisedto a position where the end effector 26 is disposed in notches 142 (FIG.21) cut from the upper surface of the lifter body 133.

After the end effector 26 has been withdrawn from the axis of the lifter128, the lifter assembly 122 is moved downwardly to deposit thesubstrate 12a on the planet 100. This is indicated by an arrow 143 inFIG. 25. As a result, the lifter assembly moves downwardly from theposition shown in broken lines in FIG. 25 to the position shown in solidlines in FIG. 25.

As will be seen in FIGS. 19 and 22A, the planet 100 is provided with alip 144 to receive and support the substrate. The lip 144 is tapered sothat, as the substrate 12a settles downwardly on the lip, it is adjustedin position and the precision of the disposition of the substrate on thelip is enhanced. The substrate 12a then becomes disposed on a ledge 145(FIG. 22A) at the bottom of the lip 144. Substantially only perimetercontact will be provided between the substrate 12a and the planet 100.Such perimeter contact is provided at the four (4) edges of thesubstrate 12a. These four (4) edges are disposed peripherally exteriorto the working area of the substrate 12 where the controlled depositionis provided.

FIGS. 22-25 schematically show the sequential operation of the alignmentassembly 110 and the lifter assembly 122. As shown in FIG. 22, thealignment assembly 110 is disposed above the planet 100 in axiallyspaced relationship to the planet and the lifter assembly 122 isdisposed below the planet in axially spaced relationship to the planet.FIG. 23 shows the disposition of the alignment assembly 110 after theaxial movement of the alignment assembly downwardly to the planet 100with the lifter assembly 122 displaced from the planet. This downwardmovement is illustrated in FIG. 23 by an arrow 145.

In FIG. 23, the drive pin 116 on the alignment assembly 110 engages thepin 120 on the planet 110 and rotates the planet 100 in accordance withthe computer controlled operation of the stepper motor 118 (FIG. 14) inrotating the alignment assembly to a precisely controlled position. Theincremental movements provided by the stepper motor 118 may becontrolled by a sensing unit generally indicated at 150 in FIG. 22. As aresult of the rotation of the planet 100a by the alignment assembly 110,the planet is in position to receive the substrate 12a on the endeffector 26 when the robotic arm assembly 24 is expanded into theprocess module 36.

FIG. 24 shows the lifter assembly 122 axially displaced upwardly asindicated by the arrow 135 and shows the substrate 12a on the lifterassembly as a result of this upward movement. It also shows thealignment assembly 110 disposed in an axially aligned position upwardlydisplaced from the planet 100a as indicated by the arrow 121. It alsoshows the end effector contracted as indicated by an arrow 141.

FIG. 25 shows the lifter assembly 122 in two (2) different positions,one indicated by broken lines and the other indicated by solid lines.The position of the lifter assembly 122 in broken lines corresponds tothe position of the lifter assembly in FIG. 24. In this position, thelifter assembly 122 has lifted the substrate 12a from the end effector26 but has not yet deposited the substrate on the planet 100a. In theposition of the lifter assembly 122 in solid lines, the lifter assemblyhas deposited the substrate 12a on the planet 100 and has moveddownwardly and axially to a position axially displaced from the planet.This is indicated by the arrow 143.

FIG. 22 shows the sensing unit, generally indicated at 150, for sensingthe rotary position of the alignment assembly 110. The sensing unit 150includes a sensor 152 for passing light from the sensing unit 150 pastthe alignment assembly 110 and through a hole 154 in the planet 100 to areflector 156 on a fixed portion of the lifter assembly 122. Thisdownward movement of the light is indicated by downwardly pointingarrows 157 in FIG. 22.

When the alignment assembly 110 has a particular rotary dispositionrelative to the reflector 156 on the lifter assembly 122, light from thesensor 152 travels past the alignment assembly 110 and through the hole154 to the reflector 156, and the light reflected by the reflector 156passes through the hole 154 and past the alignment assembly to thesensor. The resultant signal on the sensor 152 indicates a homingposition. At this homing position, the planet is aligned relative to theend effector 26 to receive the substrate 12a from the end effector.

The discussion above has related to the transfer of the bottom one 12aof the substrates 12 in the cassette 52 to one (the planet 100a) of theplanets 100 in the process module 36. It will be appreciated that thereare four (4) planets in the process module 36 and that each one of theplanets receives a substrate. Thus, when one (1) of the planets 100 hasreceived an individual one of the substrates 12, the turntable 102rotates the planets on the turntable axis to the position where the nextone of the planets has moved to the position for the transfer of thenext one of the substrates in the cassette 52 to such planet.

At the same time, the robotic arm assembly 24 in the contractedrelationship rotates to face the cassette 52, expands into the cassetteto have the end effector 26 select the bottom one of the substrates inthe cassette, contracts and then rotates with the end effector throughan angle of 180° in the contracted relationship. When the next one ofthe planets has rotated on its own axis to the position for receivingthe substrate 12 on the end effector 26, the robotic arm assembly 24expands to move the end effector into the process module 36. Thesubstrate 26 is then transferred to such next one of the planets.

In this way, the four (4) bottom substrates 12 in the cassette 52 aretransferred in sequence to the four (4) planets 100 in the processmodule 36. The four (4) substrates are then ready to be processedsimultaneously in the process module 36 to receive controlleddepositions. Although four (4) planets 100 are provided in the processmodule 36 in the embodiment of this invention, it will be appreciatedthat a number other than four (4) planets 100 can be provided in theprocess module. From the standpoint of the average amount of time toprocess substrates, more than four (4) planets 100 in the process module36 may be considered to be more efficient than four (4) modules.However, more than four planets 100 in the process module 36 may beconsidered to provide a crowding of the planets in the process module.

In the embodiment shown in FIGS. 24 and 25 and as best seen in FIG. 14,the substrate 12a is disposed on the planet 100a at the bottom of thepole pieces 108. Since the substrate 12 is not centered verticallyrelative to the pole pieces 108, there may be some bowing or bending inthe magnetic field as the flux lines in the magnetic field pass throughthe substrate.

In the embodiment shown in FIG. 26, the planet 100a is provided with anupwardly disposed flange 160 so that, when disposed on the planet, thesubstrate 12 is positioned at a median position between the top andbottom of the pole pieces 108. This causes the flux lines in themagnetic field to pass through the substrate 12 in a directionsubstantially perpendicular to the substrate. As a result, there is nobowing of such flux lines.

As will be appreciated, a vacuum is produced in the process module 36when the controlled deposition is produced on the substrate 12. Thevacuum is monitored by a vacuum sensing switch 162 (FIG. 2) extendinginto the process module 36 from the top of the process module 36. Theconstruction of the vacuum sensing switch 162 is known in the art.

FIGS. 27-29 show an arrangement for providing the controlled depositionon the substrate when there is a suitable vacuum in the process module36. The arrangement shown in FIGS. 27-29 incudes the turntable 102, oneof the planets 100 (the planet being rotatable on a different axis thanthe turntable axis) and a stator 164 rotatable on the same axis as theturntable.

The turntable 102 is attached as by bolts 166 (FIG. 27) to the hub 104.The hub 104 is in turn driven by a motor 170 which may be a servo motorand not a stepper motor. The hub 104 may be mounted through a vacuumbearing/seal assembly generally indicated at 167. The assembly 167provides a radial support for the turntable 102. An axial support forthe turntable 102 may be provided by the assembly for the motor 170. Thestator 164 is attached as by bolts 172 to a hub 174 co-axial with thehub 104. The hub 174 is rotatable relative to the hub 174 on bearings176 disposed between the hubs 104 and 174. A hex spline 178 is disposedwithin the hub 174.

A one-way clutch 180 is attached to a shaft 182 (FIGS. 27 and 29)extending from the hex spline 178. The clutch 180 may be a conventionaltype of one-way clutch. A pair of X-braces 186 are connected as byscrews 184 to the clutch 180 such that the center positions of theX-braces are disposed at the axial center of the clutch. The X-braces186 are disposed at their opposite ends in sockets in the housing 43 andare attached at their opposite ends to the housing as by bolts 188 and190 (FIG. 5). The cover 42 (FIG. 27) is disposed above the X-braces 186to enclose the process module 36.

A metal spacer 192 (FIG. 29) is disposed above the X-braces 186 andbelow the cover 42 (FIGS. 1 and 2). The spacer 192 may be slightlyoversized in the vertical direction, thereby causing the cover 42 to beslightly bowed when the process chamber is at atmospheric pressure. Thisslight bowing is compensated by the differences between the atmosphericpressure above the cover 42 and the pressure inside the process module36 when there is a vacuum pressure inside the process module.

As previously described, the motor 170 (FIG. 27) rotates the turntable102 during the time that the planets 100 are being rotated on theturntable axis to position the planets in sequence to receive individualones of the substrates from the end effector 26. During this time, thestator 164 is rotatable because it is decoupled from the X-braces 186 bythe clutch 180. However, the planets 100 are rotated relative with thestator 164 by the alignment assembly 110 to receive the individual oneof the substrates 12 from the end effector 26.

After the individual ones of the substrates 12 have been transferred tothe planets 100, the planets are rotated during the time that thecontrolled deposition is being provided on the surfaces of thesubstrates. This is accomplished by rotating the turntable 102 in adirection opposite to the direction in which the turntable is rotated asdescribed in the previous paragraphs. During the rotation of theturntable 102 in this opposite direction, the one-way clutch 180 iseffective in preventing a rotation of the stator 164 against therotation of the turntable.

When the turntable 102 rotates in the opposite direction, the motion ofthe planets 100 on the turntable about the stator 164 in turn causes theplanets to rotate on their own axis. The rotary speed of the planets 100is relatively great when driven by the stator 164 in comparison to themovement of the planets in the opposite direction with the turntable.This results from the relative diameters of the stator 164 and theplanets 100. The rotation of the planets 100 at a relatively great speedis desirable in providing for the production of a uniform deposition onthe surfaces of the substrates 12.

Two idler assemblies generally indicated at 194 in FIGS. 15-19 areprovided for pressing each planet 100 against the stator 164. Each idlerassembly 194 includes an idler 200 (FIG. 18) disposed in abuttingrelationship with an associated one of the planets 100 for rotation inaccordance with the rotation of the associated planet. Each idler 200 issupported on a pin 202 and is rotatable relative to the shaft as by aball bearing assembly 204. The pin 202 extends into the turntable 102.

A heat shield 198 is disposed above the idler 200 and is attached to theturntable 102 by retainer pins 206 (FIGS. 17 and 18) which are screwedinto the turntable 102 through a stand-off 196 (FIGS. 15 and 16). Theheat shield 198 is provided with a reflective surface to reflect heat. Aspring washer 207 (FIG. 18) is disposed against the idler 200 to providea steady force against the idler. The spring washer 207 provides for thetightening of the pin 202 against the spring washer. The spring washer207 in turn provides a force against the idler 200. The spring washer207 compensates for slight variances in tolerances in the differentcomponents in the idler assembly 194.

Helical springs 208 are disposed in sockets 209 in a slidable block 205which in turn is disposed within sockets 211. The helical springs 208apply forces through a slidable block 205 against the planet 100 so thatthe planet will be coupled to the stator 164 to rotate in accordancewith the rotation of the stator. In this way, the idler assembly 194 isfree to move radially toward the axis of the turntable 102 because thesockets 211 in the turntable allow the pin 202 to move with the slidableblocks 205.

FIG. 19 is a fragmentary sectional view taken substantially on the line19--19 of FIG. 15 and shows the relationship between one of the planets100, the turntable 102 and the stator 164. As will be seen, the stator164 is disposed above the turntable 102 and the planet 100 is spacedfrom the turntable in substantially the same horizontal planes as theturntable and the stator. The planet 100 has at progressive verticalpositions a lip portion 210 extending radially outwardly in a transversedirection with progressive vertical positions, a substantially verticalportion 212 at the upper end of the lip portion 210 and a lip portion214 extending, at progressive vertical positions, radially inwardly in atransverse direction from the upper end of the vertical portion 212. Thestator 164 has portions 216, 218 and 220 respectively corresponding indisposition and configuration to the portions 210, 212 and 214 of theplanet 100.

The transverse lips 210 and 216 respectively on the peripheries of theplanet 100 and the stator 164 abut each other. This causes the planet100 to rotate in accordance with the rotation of the stator 164. Thevertical portions 212 and 218 respectively on the peripheries of theplanet 100 and the stator 164 also abut each other to facilitate therotation of the planet 100 with the stator 164. As previously described,each planet 100 may have a tendency to ride upwardly as it rotatesbecause of its relatively heavy weight.

The upward movement of each planet 100 is limited by the contiguousdisposition of the transverse lips 214 and 220 respectively on theplanet 100 and the stator 164.

As previously described, the permanent magnets 106 have a particulardisposition such as shown in FIGS. 20, 30 and 31. This causes themagnetic field produced by the permanent magnets 106 and the pole pieces108 to have a particular disposition relative to the substrates 12 whenthe substrates are disposed on the planets 100 and are thereafterrotated. In a first rotation of the planets 100, the planets 100 may beconsidered to have a disposition relative to the permanent magnets suchas shown in FIG. 30. During this rotation, a first controlled depositionis produced by a gun, generally indicated at 222 in (FIGS. 27 and 33),on each of the planets.

In order to insure that the controlled deposition is substantiallyuniform throughout the surface area of each substrate 12, the substratemay be lifted from each associated planet and rotated through an angleof substantially 90° after the completion of the first controlleddeposition. Such lifting and rotation of the substrate 12 may beprovided by the lifter assembly 122 in a manner similar to thatdescribed above. The substrate 12 may then be deposited again on itsassociated planet 100. The planet 100 is then rotated and the associatedgun 222 is operated to produce a second controlled deposition on thesubstrate. This deposition may have the same characteristics such asthickness as that provided by the first deposition.

In this way, the second controlled deposition compensates for thedirection of the magnetic field produced by the permanent magnets 106and the pole pieces 108 during the first controlled deposition. This maybe seen from a comparison in FIGS. 30 and 31 of the disposition of thesubstrate 12 relative to the permanent magnets 106 in the firstcontrolled deposition (FIG. 30) and the second controlled deposition(FIG. 31). This causes the uniform characteristics of the resultantdeposition to be enhanced and the binary bits recorded by the magneticheads (not shown) incorporating the die on the substrates to be spacedcloser together than if only a single deposition is provided on thesubstrates.

One of the guns 222 is shown in additional detail in FIG. 27. It may beconstructed as shown in FIG. 27 in a manner well known in the art. Thegun 222 is operated to provide the controlled deposition on one of thesubstrates 12. However, the gun 222 has a warm-up period during whichits operation is not uniform. Thus, if the gun 222 were allowed toprovide the deposition on the substrate 12 during this warm-up period,the deposition on the substrate would not be uniform.

To prevent a non-uniform deposition from being provided on the substrate12, a shutter 224 (FIGS. 32 and 33) is rotated on a post 225 to aposition covering the gun 222. The rotation of the shutter 224 to acovering position is provided by a motor 226 and a belt 228 coupled tothe motor and to the post 225. When the gun 222 is operating on a steadystate basis rather than a transient basis, the shutter 224 is opened toprovide for the controlled deposition by the gun on the surface of thesubstrate 12.

As will be seen from FIG. 32, the areas of the shutters 224 arerelatively limited. Because of these limited areas, the shutters 224 maynot always be able to block the associated guns 222 from providingdepositions on the substrates when the shutters are in the closedpositions. To overcome this potential problem, shutters 230 may beprovided as shown in FIGS. 35 and 36. As will be seen, the shutters 230have a significantly greater area than the shutters 224. This assuresthat the shutters 230 will cover the substrates 12 in their closedpositions.

In order to provide for the movement of the shutters 230 between theopen and closed positions, the housing 43 in the process module 36 isprovided with bay windows 233 outboard of the housing for receiving theshutters in the open position of the shutters. The shutters 230 aremovable into the bay windows 233 through openings 236 in the housing 43.FIG. 36 shows the shutters 230 in broken lines in the open position andin solid lines in the closed position.

FIGS. 4 and 34 illustrate an assembly generally indicated at 234 forheating the substrates 12 and for preparing the surfaces of thesubstrates to receive the controlled deposition. The assembly 234 may beconsidered to be known in the prior art. The assembly 234 includes aheating element 235 (FIG. 34) such as a quartz halogen heating element.A reflector 236, preferably gold plated, is disposed above the heatingelement 235 to reflect heat from the heating element downwardly towardthe substrate 12. The shield 46 (also shown in FIG. 4) with theapertures 48 is disposed to pass hot air above the reflector 236 intothe atmosphere and to introduce cool air into the assembly 234. A fan237 disposed with in a compartment 238 above the reflector 236 tofacilitate the passage of cool air into the assembly and the flow of hotair from the assembly.

A window 240 made from a suitable material such as quartz passes theheat from the heating element 235 to the substrate 12. A heat shield 242disposed between the window 240 and the substrate 12 focusses the heaton the substrate. An ion mill 244 disposed below the substrate 12 etchesthe bottom surface of the substrate. This is the surface that receivesthe controlled deposition, which may be a suitable insulating materialsuch as aluminum oxide.

The etching of the bottom surface of the substrate 12 by the ion mill244 provides a fresh and clean surface for receiving the controlleddeposition of the aluminum oxide. This fresh and clean surface providesfor an enhanced adherence of the deposition such as aluminum oxide onthe surface of the substrate 12 and for an enhanced uniformity of thedeposition. The deposition of the aluminum oxide on the surface of thesubstrate 12 preferably has an index of refraction of at least 1.63since this index of refraction provides the deposition with dense andhard characteristics.

FIGS. 3, 4 and 5 show the relative disposition of various assemblies inthe process module 36. For example, FIGS. 3 and 4 show the dispositionof the aligned assembly 110 in the process module, and FIG. 3 shows thedisposition of the lifter assembly 122 in the process module 36. FIG. 4shows the relative disposition of the assembly 234 for heating thesubstrate 12 and etching the bottom surface of the substrate. FIG. 5shows the relative disposition of one of the guns 222 for providing thecontrolled deposition on the substrate 12. FIG. 5 also shows therelative disposition of the lifter assembly 122.

FIGS. 37 and 38 show an assembly generally indicated at 246 forproducing sputtered atoms of a material such as aluminum for movementtoward the substrate 12. The assembly 246 may be constructed in a mannerwell known in the art. The assembly 246 includes a target 248 (FIG. 38)which may be hollow and may have a frusto-conical configuration on itsinner periphery. An anode 250 may be disposed within the hollow innerperiphery of the target 248. Conduits 252 (FIG. 37) may receivede-ionized water for cooling the target. Wires may be passed through theconduits 252 to introduce a voltage to the target relative to thevoltage introduced to the anode 250. Conduits 254 may receive water forcooling the anode 250.

An assembly generally indicated at 256 may be constructed in a mannersubstantially identical to that shown in FIG. 37 for the assembly 246.The assembly 256 is provided with a target 258 substantiallycorresponding to the target 246 and with an anode 260 substantiallycorresponding to the anode 250. As shown in FIG. 38, the target 248 andthe anode 260 are connected to one terminal of a source 262 ofalternating voltage. The source 262 may provide the alternating voltageat a suitable frequency such as a frequency between approximately fortykilohertz (40 Khz) and approximately one hundred Kilohertz (100 KHz).The target 258 and the anode 250 are connected to the other terminal ofthe alternating voltage source 262. The combination of the assemblies246 and 256 is considered to be well known in the art. The arrangementshown in FIG. 38, including the connections to the voltage source 262,is also considered to be unique to the system and method of thisinvention.

In alternate half cycles of the alternating voltage from the source 262,the target 248 receives a negative voltage and the anode 250 receives apositive voltage. In these alternate half cycles, the electrons emittedfrom the anode 250 travel in a circuitous path to the target 248. Thepath is circuitous because of the electrical field in one directionbetween the anode 250 and target 248 and because of the magnetic fieldproduced by the permanent magnets 106 and the pole pieces 108 in adirection substantially perpendicular to the electrical field. Thiscircuitous path for the movement of the electrons enhances theionization of argon molecules by the electrons. The argon molecules aredisposed in the space between the target 248 and the anode 250.

The enhanced ionization of the argon molecules in turn enhances thesputtering produced by the argon molecules of the atoms of the elementsuch as aluminum from the surface of the target 248. In the other halfcycles of the alternating voltage from the source 262, the anode 250receives a negative voltage and the target 248 receives a positivevoltage. This interrupts the flow of electrons from the anode 250 to thetarget 248 and causes the electrons to flow in a direction away from thetarget and toward the anode.

By controlling the flow of electrons in this manner, the number of theelectrons in the space between the target 248 and the anode 250 isincreased. This increases the rate of producing argon atoms in the spacebetween the target 48 and the anode 250 and increases the rate at whichatoms are sputtered from the surface of the target and deposited on thesubstrate 12.

In like manner, electrons flow from the anode 260 to the target 258 inthe other half cycles. In the alternate half cycles, the negativevoltage on the anode 260 causes the flow of electrons to the target 258to become interrupted and the electrons to flow toward the anode 260.Thus, the assembly 256 operates in the same manner as the assembly 246except that it is 180° out of synchronization with the assembly 246.

The substrate 12 rotates on an axis such that the assembly 246 isdisposed on one side of the axis and the assembly 256 is disposed on theother side of the axis. In this way, the assemblies 246 and 256 act inopposite phases on opposite sides of the substrate 12 on the planet 100.By providing alternating voltages between the anode and the cathode ineach of the assemblies 246 and 256, the effectiveness of the electronsin producing ions from the argon molecules in the space between theanode and the target is enhanced. This results from the fact that theelectrons travel in alternate half cycles from the anode to the targetand in the other half cycles from the target to the anode, therebyincreasing the opportunity of the electrons to impinge upon and ionizeargon molecules. It also results from the fact that two (2) assemblies(246 and 256) act upon the substrate in each revolution of the substratein sputtering atoms on the surface of the substrate. Furthermore, two(2) assemblies act in phase opposition to each other.

Applicants have discovered that the uniformity of the controlleddeposition on the surface of each substrate 12 can be even furtherenhanced by providing a shutter 264 shown schematically (FIG. 39) at aparticular position at or near the periphery of each planet 100. Theshutter 264 is fixedly disposed relative to the associated planet 100 byextending the shutter radially inwardly from a position at the externalperiphery of the planet to a position between the external periphery ofthe planet and the center of the planet. The operation of the shutter264 in enhancing the uniformity of the controlled deposition on thesubstrate 12 is not fully understood at this time.

FIG. 40 is a flow chart, generally illustrated at 300, illustrating theoperation of the apparatus shown in FIGS. 1-39 and described above. As afirst step in such operation, the system is powered up to provide asteady state operation of the different components, including voltagesupplies, in the system. The system is also initialized. For example,the cassette 52 is moved to the position where the first substrate canbe disposed on the cassette. The power up and initializing step is shownat 302 in FIG. 40.

As a next step, the system is pumped down to provide a vacuum in thecassette module 14, the transport module 22 and the process module 36.This step is illustrated at 304 in FIG. 40. The slot valve 34 betweenthe cassette module 12 and the transport module 22 is then closed toisolate the transport module from the cassette module. A block 306 inFIG. 40 illustrates this step.

The load lock 15 is then vented to the atmosphere as illustrated by ablock 308 in FIG. 40, and the substrates 12 are loaded in the cassette52 as illustrated at 310. The load lock 15 (FIG. 1) is then closed andthe slot valve 34 is opened. A vacuum is then produced in the cassettemodule 14, the transport module 22 and the process module 36. This isillustrated at 312 in FIG. 40.

The different components are subsequently moved to their home positionsas illustrated at 314 in FIG. 40. For example, the robotic arm assembly24 is moved to a contracted relationship with the end effector 26 facingthe cassette module 22. The alignment assembly 110 is moved axiallyupwardly to a position displaced from any of the planets 100 and thelifter assembly 122 is moved axially downwardly to a position displacedfrom any of the planets 100. The turntable is also rotated to a homeposition pre-programmed into the microprocessor 147.

The turntable 102 is then moved to a particular position providing for adisposition of one of the planets 100 in axially aligned relationshipwith the alignment assembly 110 and the lifter assembly 122. Thisrotation is pre-programmed into the microprocessor 147. At the sametime, the robotic arm assembly 24 is expanded to move the end effector26 into the cassette module 14 so that the end effector can receive thebottom one of the substrates 12a in the cassette module 52. The cassette52 is then moved downwardly to deposit the substrate 12 on the endeffector 26. The robotic arm assembly 24 is then contracted and therobotic arm assembly and the end effector 26 are rotated through anangle of 180° so that the end effector faces the process module 36. Ablock 316 illustrates the steps described in this paragraph.

The alignment assembly 110 is now moved downwardly (see block 317) sothat the pin 116 (FIG. 23) in the alignment assembly engages the pin 120on the planet 110a. The alignment assembly 110 then rotates the planet100a to position the planet for receiving the substrate 12a on the endeffector 26. The step for providing such alignment is illustrated at 318in FIG. 40. This step is provided under a control of the microprocessor319 in FIG. 1. (The microprocessor 319 is shown in FIG. 1 as beingconnected by a bus 321 to the process module 36). The alignment assemblyis then moved upwardly (block 319) to withdraw the alignment assemblyfrom the planet 100a. The robotic arm assembly 24 is then expanded tomove the substrate 12a to a position above the planet 100a and thelifter assembly 122. This is illustrated at 320 in FIG. 40.

The lifter assembly 122 is now moved axially upwardly into position forreceiving the substrate 12a on the end effector 26. A block 322 in FIG.40 illustrates this step. The robotic arm assembly 24 is then contractedso that the end effector is out of the way of the lifter assembly 122.The contraction of the robotic arm assembly is illustrated at 324 inFIG. 40.

The lifter assembly 122 is now moved axially downwardly to have thelifter assembly deposit the substrate 12a on the planet 100a, asillustrated at 326 in FIG. 40. The lifter assembly 122 is then movedaxially downwardly to a position axially displaced from the planet 100a.The turntable 102 is then indexed by the microprocessor so that the nextone of the planets 100 in the rotary direction is axially aligned withthe alignment assembly 110 and the lifter assembly 122.

The steps described above and shown in blocks 318-326 are now performedto dispose the next one of the substrates 12 in the cassette 52 on thenext one of the planets 110. The steps described in this paragraph arethen performed until all of the planets 100 have received individualones of the substrates 12. The steps described in this paragraph and theprevious paragraph for disposing the substrates 12 on the planets 100are illustrated at 328 in FIG. 40.

The first controlled depositions are now provided by the guns 222 on thesubstrates 12 in the process module 36 as illustrated at 330 in FIG. 40.When the first controlled depositions have been completed, thesubstrates 12 are lifted in sequence by the lifter assembly 122 and thesubstrates 12 are rotated through an angle of 90° and deposited again ontheir respective planets 100. This is illustrated at 332 in FIG. 40. Thesecond controlled depositions are now provided by the guns 222 on thesubstrates as illustrated at 334 in FIG. 40.

After the first and second controlled depositions have been provided onthe substrates 12 in the process module 36, the substrates 12 arereturned to the cassette module 14 for removal from the cassette module.The sequence of steps for providing the return of the substrates 12 tothe cassette 52 in the cassette module 14 is the inverse of the stepsshown in blocks 304-334. This inverse of such steps is indicated by ablock 336 in FIG. 40.

The apparatus and method described above have certain importantadvantages. They provide for a full sequence of operations--from thestep of loading the substrates into the cassette module to thedisposition of the substrates on the planets 100 and then to thecontrolled depositions on the substrates. They also provide for a fullsequence in an inverse order to provide for a return of the substrates12 to the cassette 52 after the controlled depositions have beenprovided on the substrates.

A number of the components and sub-assemblies in the cassette module 14and the process module 36 are also considered unique in applicants--system. For example, the relationship between the turntable 102, thestator 164 and the planet 100 in positioning the substrates 12 fordisposition on the planets 100 and in providing for the controlleddepositions on the substrates are considered to be unique in theapparatus and method of this invention. The construction and operationof the alignment assembly 110 and the lifter assembly 122 are alsoconsidered to be unique in the apparatus and method of this invention.The controlled movements of the substrates 12 to the position fortransfer to the planets 100 are also considered to be unique to theapparatus and method of this invention.

FIGS. 41-48 illustrate an improvement in the system shown in FIGS. 1-40and described above. Such improvement includes a stator 400corresponding to the stator 164 described above. However, the stator 400includes teeth 402 on its periphery. The teeth 402 are precisely formed.For example, each of the teeth 402 may be formed as by a milling machineto have a sinusoidal shape. The stator 400 is rotatable on an axis 404in FIG. 41.

The teeth 402 on the periphery of the stator 400 are in mesh with teeth406 on the periphery of planets 408 rotatable on axes 410 displaced fromthe axis 406. The planets 408 correspond to the planets 100 in theembodiment shown in FIGS. 1-40. The teeth 406 on the periphery of theplanets 408 are formed in a manner similar to the formation of the teeth402 on the stator 400. Thus, there is no slippage between the teeth 402on the stator 400 and the teeth 406 on the planets 408 as the planetsrotate relative to the stator. This is particularly shown in FIG. 44 bythe precise meshing of teeth 402a and 406a respectively on the stator400 and one of the planets 408. This results from the fact that theteeth 402 on the stator 400 fit precisely into the teeth 406 on theplanets 408 so that there is no slippage between the teeth on the statorand the teeth on the planets as the planets rotate relative to thestator.

An O-ring 414 made from a suitable resilient material such as neopreneis tightly disposed on the stator 400 at a position below the teeth 402on the stator. The O-ring 414 is engaged by the planets 408 at aposition below the teeth 406 on the planets. The engagement of theO-ring 414 by the planets 408 is relatively tight because idlers 416press the planets against the O-ring. The idlers 416 correspond to theidlers 192 in the embodiment shown in FIGS. 1-40 and described above.

The turntable 102 rotates the planets 408 on the axis of the turntableso that the planets rotate past a gun 420. The gun 420 corresponds tothe gun 222 in the embodiment shown in FIGS. 1-40 and described above.In addition to rotating on the axis of the stator 400, the planets 408rotate on their own axes 410 as the turntable rotates the planets. Sincethe substrates 12 are disposed on the planets 408, they have the samepath of movement as the planets.

FIG. 47 illustrates the relative dispositions of the gun 420, one of theplanets 408 and the substrate 12 on such planet during one pass of suchplanet and such substrate past such gun. The area covered by the gun 420on such planet 408 and such substrate 12 is indicated as cross-hatchingat 422 in FIG. 47. As will be appreciated, the area covered by the gun420 on such planet 408 and such substrate 12 is not the same in eachsuccessive movement of such planet 408 and such substrate 12 past thegun. This results from the rotations of the planets 408 and thesubstrates 12 relative to the stator during the rotation of the planetsand the substrates by the planet. This may be seen from FIG. 48 wheredark cross hatched areas 426 indicate a greater thickness of depositionon the substrate than the thickness of the deposition in the light crosshatched areas 428.

After a particular number of successive movements of each planet 408 andeach substrate 12 past the gun 420, however, the thickness of thedepositions on the substrate is the same at every position on thesubstrate. It is important, however, that the movement of the planet 408and the substrate 12 past the gun 420 be discontinued precisely at theend of the particular number of passes (e.g. 11).

If the movement of any of the planets 408 and the substrate 12 on thatplanet is continued for any time after the particular number of passes(e.g. 9), there will be a greater thickness of the deposition on thesubstrate at some positions than at other positions on the substrate. Aswill be appreciated, this is not desirable because it may result in therecording of imprecise information on the substrate and the subsequentreading of such imprecise information from the substrate.

Similarly, if the movement of any of the planets 408 and the substrate12 on that planet is discontinued for any time before the particularnumber of passes (e.g. 11), there will be a decreased thickness of thedeposition on the substrate at the positions where there is less thanthe particular number (e.g. 11) of passes than at the positions wherethere is the particular number of passes.

The improvements shown in FIGS. 41-48 and described above provide for adeposition of a substantially uniform thickness by limiting the movementof the substrate 12 past the gun 420 to a precise number of passes. Thisresults in part from the precise meshing between the teeth 402 on thestator 400 and the teeth 406 on the planets 408. It also results fromthe fact that the O-ring 414 provides an instantaneous braking action tostop the movement of the stator 400 and the planets 408 when the motorfor driving the stator is de-energized. The instantaneous braking actionoccurs because of the flattening of the O-ring 414 at the position onthe O-ring where the stator 400 and one of the planets 408 engages theO-ring. This is indicated schematically at 430 in FIG. 46. Thisflattened disposition inhibits any movement of the stator 400 and theplaten unless the motor driving the stator is energized. Such flatteningof the O-ring 414 also generates heat and dissipates energy therebyinhibiting movement of the stator 400 and the planets 408 when the motorfor driving the stator turntable 102 is deenergized.

Although this invention has been disclosed and illustrated withreference to particular embodiments, the principles involved aresusceptible for use in numerous other embodiments which will be apparentto persons skilled in the art. The invention is, therefore, to belimited only as indicated by the scope of the appended claims.

What is claimed is:
 1. An apparatus for providing a deposition on aplurality of substrates, including,a cylindrical stator having aperiphery and having teeth on its periphery, a plurality of planets eachconstructed to support one of the substrates and each rotatable relativeto the stator relative to and each having a periphery and having on itsperiphery a plurality of teeth in mesh with the teeth on the peripheryof the stator, each of the planets being constructed to support anindividual one of the substrates for rotation with such planet, meansenergizable to rotate the planets, means for pressing the planetsagainst the stator, means disposed on the stator at a position displacedfrom the teeth and in coupled relationship with the planets forproviding a braking action on the planets to provide an instantaneousinterruption in the rotation of the planets relative to the stator whenthe energizable means becomes de-energized, and a gun disposed relativeto the planets for producing a deposition on the substrates inaccordance with the rotation of the planets when the substrates aredisposed on the planets, wherein the braking means constitutes an O-ringdisposed on the stator at a position displaced from the teeth on thestator and the teeth on the planets and wherein the planets pressagainst the O-ring on the stator to distort the O-ring at such pressingpositions.
 2. An apparatus for providing a deposition on a substrate,including,a stator having a periphery and having teeth on its periphery,a planet constructed to support the substrate on the planet and havingon its periphery a plurality of teeth in mesh with the teeth on theperiphery of the stator to provide for the rotation of the planetrelative to the stator on a particular axis, energizable means forrotating the planet on the first particular axis, a member disposed onthe stator at a position displaced from the teeth and in coupledrelationship with the planet for providing a braking action on theplanet to provide an instantaneous interruption in the rotation of theplanet relative to the stator when the energizable means becomesde-energized, and a gun disposed relative to the planet for producing adeposition on the substrate in accordance with the rotation of theplanet relative to the stator when the substrate is disposed on theplanet and the energizable means is energized, wherein the memberconstitutes a deformable O-ring with resilient characteristics andwherein the stator has a first portion with the teeth on its peripheryand has a second portion displaced from the first portion and whereinthe second portion is without the teeth and wherein the member isdisposed on the second portion of the stator and is made from adeformable material with resilient characteristics and wherein themember is in the form of an O-ring and wherein the planet has a firstportion with the teeth on its periphery and has a second portiondisplaced from the first portion and wherein the second portion of theplanet is without teeth and wherein the O-ring engages the secondportion of the planet.
 3. An apparatus for providing a deposition on asubstrate, including,a stator rotatable on a first particular axis andhaving a first portion and a second portion, a planet directed in acoupled relationship to the stator for rotation relative to the statoron a second particular axis, a member disposed on the second portion ofthe stator, a motor energizable to rotate the planet on the secondparticular axis, the planet having a first portion coupled to the firstportion of the stator for rotation of the planet, without slippage,relative to the stator and having a second portion coupled to the memberfor acting on the member to provide an instantaneous braking action onthe stator and the planet when the motor is de-energized, and a gundisposed relative to the second axis of the planet for providing acontrolled deposition on the substrate on the planet during theenergizing of the motor,wherein the first portions of the stator and theplanet are provided with a meshing relationship for a rotation of theplanet relative to the stator without any slippage in accordance withthe rotation of the planet by the energizable means and wherein themeshing relationship between the stator and the planet is provided bysinusoidal teeth on the first portion of the stator and the planet andwherein the member contributes a resilient O-ring disposed on the secondportion of the stator and engaging the second portion of the planet toprovide the braking action between the second portion of the stator andthe second portion of the planet when the energizable means isenergized.